Air conditioner control mechanism



W. W. BELL, JR

AIR CONDITIONER CONTROL MECHANISM July 13, 1965 2 Sheets-Sheet 1 Filed June 22, 1964 INVENTOR.

WILLIAM W. BELL, JR.

ATTORNEY.

y 13, 1965 w. w. BELL, JR 3,194,028

AIR CONDITIONER CONTROL MECHANISM Filed June 22, 1964 2 Sheets-Sheet 2 FIG. 4

INVENTOR.

WILLIAM W. BELL, JR.

Wzam

AT TORNEY.

United States Patent 3,194,028 AER CONDITIONER CONTROL l /ECl-IANEM William W. Bell, Jr., Marcellus, N.Y., assign'or to Carrier Corporation, Syracuse, N .Y., a corporation of Delaware Filed June 22, 1964, Ser. No. 376,711 11 Claims. (Cl. 62180) This invention relates to air conditioning apparatus, and more particularly, to a control mechanism for dampers employed in self-contained air conditioners.

It is desirable that air conditioning apparatus, such as room type air conditioners, be capable of bringing outside ventilating air into the area being conditioned and exhausting stale air from the area being conditioned, in addition to its usual conditioning or cooling function. To ventilate and exhaust, the conditioning apparatus is normally provided with internal passages communicating the area being conditioned with the outside ambient. The how of air through the conditioner passages may be regulated by dampers selectively operated by means of a control mechanism located at a convenient point on the exterior of the conditioning apparatus. Damper control mechanisms, however, are often complicated and expensive, sometimes exceedingly difficult of operation and subject to Wear, binding, and slippage.

It is a principal object of the present invention to provide a control mechanism for dampers employed in air conditioning apparatus which obviates the deficiencies and disadvantages of prior constructions.

It is a further object of the present invention to provide a simplified ventilation and exhaust damper control mechanism for use in air conditioning apparatus for selectively positioning ventilation and exhaust dampers without excessive manual efiort.

It is an object of the present invention to provide an inexpensive damper control mechanism for air conditioning apparatus providing a simple straight-line actuating movement to adjust a selected damper to a desired operating position.

This invention relates to an air conditioning unit comprising in combination a casing forming a first chamber and a second chamber, a refrigeration system in the casing including an evaporator in the first chamber and a condenser in the second chamber, fan means for moving a first air stream over the evaporator and a second air stream over the condenser, at least one passageway connecting the first chamber and the second chamber, a damper for closing the passageway, means for resiliently holding the damper in closed position, and means for actuating the damper to open the passageway against the resistance of the resilient holding means, the damper actuating means including a support member, a control member, a cable connecting the damper with the control member, means for mounting the control member on the support member to provide simultaneous pivotal movement and generally lateral movement of the control member with relation to the support member, movement of the control member in a desired direction actuating the damp er to open the passageway against the resistance of the resilient means, a member extending from the control member to provide manual operation of the control member, and means connecting the extended member and the support member to limit movement of the extended member to a direction generally longitudinally of the support member whereby generally longitudinal movement of the extended member pivots the control member and simultaneously moves the control member in a generally lateral direction with relation to the support member.

Other objects will be apparent from the ensuing drawings and description in which:

FIGURE 1 is a perspective view of an air conditioning apparatus embodying the present invention;

ICC

FIGURE 2 is a view partially in section illustrating the damper controlling mechanism of the invention;

FIGURE 3 is a view partially in section illustrating a modification of the damper controlling mechanism shown in FIGURE 2; and p v FIGURE 4 is a view partially in section illustrating a second modification of the damper controlling mechanism shown in FIGURE 2.

Referring to FIGURE 1 of the drawings, there is shown an air conditioning unit 10 embodying the present invention. Unit 10 comprises a casing 11 containing a refrigeration system including compressor 13, condenser 14, expansion means 15, and evaporator 16 interconnected by suitable conduit means (not shown) to form a closed path for refrigerant flow.

The air conditioning unit 10 may be placed in a Window or through a wall so that inlet 20 and outlet 21 in the front face thereof communicate with the room to be conditioned while the opposite end or rear face thereof communicates with an area outside the room. Operating controls 25 for the air conditioning unit may be placed on the front face of casing 11.

A partition member 27 in cooperation with evaporator fan scroll partition member 39 and side 31 of partition member 30 separates casing 11 into evaporator compartment 23 and condenser compartment 29. A fan motor (not shown) is secured to the partition member 27. Evaporator fan 32 is secured to one end of the fan motor in the space between partition member 27 and side 31 of partition member 30 while condenser fan 33 is secured to the opposite end thereof. Compressor 13, condenser 14, condenser fan 33, and, if desired, expansion means 15 are disposed in condenser compartment 29 while evaporator 16 and evaporator fan 32 are disposed in evaporator compartment 28.

Partition member 30 has a generally inverted L shape. Side 31 of partition member 30 is provided with fan inlet opening 38 therein. Side 34 of partition member 30 cooperates with evaporator fan scroll partition member 39, side 27' of partition member 27, and unit casing 11 to define a discharge chamber 42. Outlet 21 in the front face of the unit 10 communicates discharge chamber 4-2 with the area being conditioned.

Evaporator fan 32 draws air to be conditioned through inlet 20 and filter 35 into heat exchange relationship with evaporator 16. The conditioned air passes through opening 38 in partition member side 31 and is discharged through discharge chamber 42 and outlet 21 into the area being conditioned. Condenser fan 33 draws outside air through louvered openings 12 in casing 11, as shown by the solid line arrow in FIGURE 1 of the drawings, into heat exchange relation with condenser 14 and discharges through an outlet in the rear face of the casing to the outside.

To exhaust stale air from the area being conditioned, a damper controlled opening 40 is provided in partition member 27 adjacent to the inlet side of condenser fan 3.3 and the discharge side of evaporator fan 32. A damper 41, journaled for rotation on shaft 43 by suitable means (not shown), regulates the flow of air through exhaust opening 40. Damper 41 is biased toward closed position by spring 49. With damper 41 open, air in evaporator compartment 28 under the influence of evaporator and condenser fans 32, 33, respectively, passes through opening 40 into condenser compartment 29 and the outside.

A flexible cable 50, secured to damper 41 by lost motion means 51, regulates the position of damper 41. Lost rnotion means 51 preferably comprises the L-shaped end of cable 50 disposed in hole 53 in damper 41. Cable 50 extends through and is movable within sheath 54 held in fixed position by suitable means. The opposite end abuts the inside of faceplate 17. A fulcrum pin 73, fixto be explained hereinafter.

'stantially parallel with front edge 71 thereof.

of flexible cable 55) is secured to control member '75 'as will be more particularly explained hereinafter.

To ventilate the area being conditioned, an opening56 is provided in panelfil of partition member 30, Damper 58, journaled for rotation on shaft 60 and biased toward closed position by suitable means (notshown), regulates the flow of outside air through. openin 56 into the area" being conditioned. With damper 58 open, air from condenser compartment 29 is drawn throughventilation opentionmeans 64 to damper 58, permits selective movement.

' ing 91 and limits movement of actuating arm 90'to a direction substantially parallel to front edge 71 of support member 79 and to faceplate 1 7 With control member 75 in the position shown in FIG- URE 2 of'the drawings,flexhaust-and ventilation dampers 4f, 53, respectively, are closed. 'With control member 87 in the position shownxin FIGURE '2 of the drawings,

thermostatic control unit 35 regulates operation of the unit ltlto maintain a preset temperature and humidity condition within the area being conditioned.

Push-button type controls, designated generally by the numeral 1%, regulate over-all operation of the air conof ventilation damper 53. .Lost motion means 64 prefer ably comprises theL-shaped end of cable 63 extending through hole 65 in damper 53. Cable 63 extends within and is movable relative to Shannen heldin fixed position bysuitable means.

Referring paticularly to FIGURE 2 of the drawings, operating controls 25 incluclea plate-like support member 7 7t fixedly secured to casing 1-1 by suitable means (not shown); The front or. forward edge71of member 70 edly secured to support member 76), extends through slotlike opening 74 in control member 75 to pivotally position control member 75 on support member 70. A suitlimited movement between control member 75 and support member 70 in a plane substantially port member 70.

Control member 75 includes an arm-like extension 76, preferably colinear with opening 74. Extension 76 overlaps front edge 71 of support member 70 to accommodate manual operation of the control member: 75 in a manner Operating linger 94 is .sej cured to'the outer end of'extension 76. Support member 70 includes a slot-like opening, 78 adjacent to and sub Pin '79,- fixed to extension '76 of control member 75 cooperates with opening 78 to limitrnovement of extension 76 .to a direction substantially parallel to the front edge 71' of support member 7 t and to faceplate l7. I 5

Cables 50, '63 are-fixedly secured tocontrol member 75 at 80, 8l,respectively, by suitable means '(not shown).

parallel to sup- Support member 70 includes suitable means for fixedly securing sheaths 54, 66 of cablesStl, 63, respectively, against longitudinal movement.

Support member 70 includes a plurality ofopenings or recesses 82, 82, 82" therein" A spring biased detent ball 83, on control member extension 76, cooperates with openings- 82,'82, 82":to releasably'retain control member 75 in preselected position.

ditioning unit N. Controls 190 turn the unit on and off, regulate the speed of the fan motor, and delimit operation of compressor 13. With controls 100 assumed to be properly adjusted to permit operation of the unit 10 under the control of thermostatic control mechanism 85, on' a demanclfor cooling,'control mechanism 85 energizes'compressor '13 and the fan motor. Condenser'fan 33. draws outside air. through louveredopenings 12 in casing Ill-into heat exchange relationship with condenser 14and discharges through the outlet in" the rear face of casing 11 into the outside. Evaporator fan 32 draws air from the area being conditioned through inlet 2% and filter 35 into heat exchange relation with evaporator 16,

. conditioned air passing throughinlet 38 in panel 31 of v partition member into discharge chamber 42 and through outletZl into the areabeing conditioned.

On movement of control member 75 in a downward direction, as shown by the solid line arrow in FIGURE 2 of the drawings, cable 5% moves exhaust damper 41 in an opening direction against the bias of spring 49. Detent ball 83 cooperates with recess 82 to retain control member '75 in the exhaust damper open position.- Movement of cable 63, which regulates ventilation damper 58, during downward movement of control member 7 5 is neutralized influence of'fans 32, 33 passes through opening 40 into condenser compartment 29 and the outside.

On movement of control member 75 in an upward dimotion from the position shown in FIGURE 2 as shown by the dotted line arrow, cable 63 moves ventilation damper 58' in an opening direction against the damper bias means (not shown). Detent ball 83 cooperates with recess S to retain control member 75 in the ventilation damper open position. Movement of cable 50, which regulates exhaust damper 41 during upward movement of control member'75, is-neutralized by lost motion means 51. 'Damper 41 accordingly remains closed.

unit 10 to maintain-selected temperature and humidity conditions in the area being conditioned- Thermostatic controlmechanism 85 includes a suitable temperature responsive element (not shown). for sensing temperature conditions in the area being conditioned. Thermostatic control mechanism 85 is fixedly secured to the support Controlmember 87 is member 70. by suitable means.

. area being conditioned; a

With ventilation damper 58 opened, outside air is drawn .from condenser compartment 29 through opening 56 by evaporator fan I 32 and discharged through. discharge chamber outlet 21 in thefront face of casing 11 into the Actuating arm 90 may be moved in the direction shown by solid line arrows in FIGURE 2 of the drawings to adfixedly secured to shaft 86 of thermostatic controlunit v 'just thermostatic control mechanism 85 to vary the response of the control mechanism to temperature and humidity conditions in the area being conditioned and, correof control member '75 .and actuating arm 90 of control member 87 toa direction substantially paralleling support laps the front edge-7 of support member 70. vl-Tinger95, I

secured to the opposite end of mass, facilitates manual movement of actuating arm 90 and adjustment of temperature control unit 35. a v

Support member includes a slot-like" opening 91 adjacent to and parallel with edge '71 thereof. Slot-like opening 91 is preferably coline'ar with opening 73. 'Pin '92, on actuating arm 90, is disposed within slot-like'opem member edg'e 71 andtherefore faceplate 17. Accordingremains substantially constant. While' applicahts control. apparatus is disclosed in a preferred embodiment as regulating plural dampers, ex-

ihaus't damper 41 and ventilation damper 58, it is understood thatthe control apparatus of 'f this'invention may be employed to regulate a single damper. In that circumstance, a single cable 50 or 63 only is connected to the control member 75.

In the embodiment shown in FIGURE 3 of the drawings, wherein like numerals refer to like parts, exhaust damper cable 50 is fixedly secured to the control member 75 between slot-like opening 74 and pin 79 at 96 by suitable means (not shown). A suitable gripping means (not shown) retains sheath 54 of cable 54} against longitudinal movement.

In the FIGURE 3 embodiment on movement of control member 75 in a downward direction as shown by the solid line arrow, cable 50 moves exhaust damper 41 in an opening direction whereby air from the area being conditioned is exhausted through opening 40 to the outside. Movement of cable 63, which regulates ventilation damper 58, is neutralized by lost motion means 64 and damper 58 remains closed. On movement of control member 75 in an upward direction as shown by the dotted line arrow, cable 63 moves ventilation damper 58 in an opening direction in the manner described heretofore in the embodiment of FIGURE 2. Lost motion means 51 neutralizes corresponding movement of cable 50 during movement of control member 75 in the upward direction so that exhaust damper 41 remains closed.

In the embodiment shown in FIGURE 4 of the drawings, applicant has provided a control apparatus elfective to simultaneously move both exhaust and ventilation dampers 41, 58, respectively. Referring to FIGURE 4 wherein like numerals refer to like parts, ventilation damper cable 63 is operably connected to control member 75 between slot-like opening 74 and pin 79 at 96. Exhaust damper cable 50 is operably connected to control member 75 at 80 as in the FIGURE 2 embodiment. Sheath 66 of cable 63 is retained against longitudinal movement by suitable gripping means (not shown). It is understood that the connections of exhaust and ventilation damper control cables 50, 63 with control member 75 may be reversed so that exhaust control cable 50 is operably con nected to control member 75 at 96 and ventilation control cable 63 is operably connected to control member 75 at 80.

Referring to FIGURE 4, on movement of control member 75 in a downward direction as shown by the solid line arrow, exhaust damper control cable 50 and ventilation damper control cable 63 move dampers 41 and 58, respectively, in an opening direction whereby air may be simultaneously exhausted and vented through openings 49, 56, respectively, between the area being conditioned and the outside.

Applicant has provided a new and improved controlling mechanism for use in air conditioning apparatus efiective to selectively regulate the air conditioning apparatus temperature control, and ventilation and exhaust dampers; a unique control mechanism eflcctive to translate simple, straight-line movement into positioning movement for a selected one of plural dampers.

While I have described a preferred embodiment of my invention, it will be understood that my invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. In an air conditioning unit, the combination of a casing forming a first chamber and a second chamber, a refrigeration system in the casing including an evaporator in the first chamber and a condenser in the second chamber, fan means for moving a first air stream over the evaporator and a second air stream over the condenser, at least one passageway connecting the first chamber and the second chamber, a damper for closing the passageway, means for resiliently holding the damper in closed position, and means for actuating the damper to open the passageway against the resistance of said resilient holding means, said damper actuating means including a support member, a control member, a cable connecting the damper with said control member, means for mounting the control member on the support member to provide simultaneous pivotal movement and generally lateral movement of the control member with relation to said support member, movement of the control member in a desired direction actuating the damper to open the passageway against the resistance of the resilient means, a member extending from said control member to pro vide manual operation of the control member, and means connecting the extended member and the support member to limit movement of the extended member to a direction generally longitudinally of the support member whereby generally longitudinal movement of the extended member pivots said control member and simultaneously moves the control member in a generally lateral direc tion with relation to said support member.

2. An air conditioning unit according to claim 1 in which said mounting means includes a generally laterally extending slot-like member and a second member extending within the slot-like member, one comprising an element of the control member and the other comprising an element of the support member.

3. An air conditioning unit according to claim 2 in which said means connecting the extended member and the support member includes a generally longitudinally extending slot-like member and a second member extending within the slot-like member, one comprising an element of the extended member and the other comprising an element of the support member.

4. In an air conditioning unit, the combination of a housing partitioned into a first compartment in communication with the area being conditioned and a second compartment in communication with the outside, a refrigeration system including an evaporator in said first compartment and a condenser in said second compartment, fan means for moving a first stream of air over the evaporator and a second stream of air over the condenser, a passage between the first and second compartments for venting the area being conditioned, a first damper for regulating said vent passage, a second passage between the first and second compartments for exhausting the area being conditioned, a second damper for regulating said exhaust passage, and means for actuating said first and second dampers including a support member having a mounting pin, a control member having a slot-like opening therein adapted to receive said mounting pin to pivotally relate said control member to said support member for limited lost motion, said control member including an arm-like part having a terminal end extending beyond said support member to accommodate manual manipulation of said control member, said support member having a first generally longitudinal slot-like opening therein, a locating pin on said control member arm-like part slidably disposed within said support member first opening to limit movement of said control member arm-like part to a substantially longitudinal direction, first and second cables securing said control member to said first and second dampers, respectively.

5. An air conditioning unit according to claim 4 in which one of said first and second cables is secured to said control member between said control member slotlike opening and said locating pin.

6. An air conditioning unit according to claim 5 in which the longitudinal axis of said control member slotlike opening and the axis of said locating pin lay within a first plane, the other of said said first and second cables being secured to said control member at a point spaced from said plane.

7. An air conditioning unit according to claim 6 in which said first and second cables are disposed on the same side of said plane.

8. An air conditioning unit according to claim 6 in which said first and second cables are disposed on 0pposite sides of said plane.

ment, fanmeans for moving a first stream of airf over the evaporator and a second stream of air over the con- 7 denser, a passage between-the firstand second compartments for venting the area being conditioned, a first damper for regulating said vent passage, a second passage between the first and second compartments for exhausting the area being conditioned, a second damper for regulating said "exhaust passage, and means forgactuatfl ing said first and second'dampers including a control member having a slot-like opening between opposite at least'one, substantially planar edge a first operator pivotally secured to said support member between oppositeends thereof forlimited lost motion, means for releasably retaining said first operator in selected posiion, a link connected between one end of said first op: erator and said first damper whereby movement of said operator 'in' one direction from a damper closed position opens said first damper against; said resilient holding means to ventthe room, a second link connected between the other end ofsaid operator and said exhaust damper whereby movement of said operator in the opposits directionfronrsaid damper closed position opens said second damper against said resilient holding means to ,exhaust'the room, said first operator having an armlike extensionwith aterminal end outside said support 'member edge to accommodate manual movement of ends thereof,fa support member having a fulcrum pin secured thereto cooperable with said control member opening to pivotally secure said .control memberto said support member for limited lost motion, a flexible cable secured to the control member; between said slot-like opening and one ofsaidcontrol member ends for'regulating operation of one of said' first and second dampers,

axis of said slot-like, opening to permit manual operation thereof, a substantially longitudinal slot-like recess in said support member, a locating pin secured, to said control member arm-like part and adaptedto be slidably received in said support member- -recess to limit move ment of said arm-like part-to a longitudinal direction, and a second flexible cable secured to said 'control member between said slot-like opening andsaid locating pin for regulating the operation of the other of said-first and second dampers. 7 a i a 10. An air conditioning unit accordingt o' claim '9 in which said control member comprises a plate-like part, said first "and second cables being disposed on one side ,of the longitudinal axis of said slot-like opening.

11. In a room air conditioner, the combination of a 'compartmenttwith a heat exchange coil therein; means adapted when actuated to supply conditioned medium to V the coil; a motor operated fan for circulating room air through the compartment; 7 a vent passage connecting the inlet side of the fan'with the'outside; a first damper said control'member having an arm-like part extending in a direction substantially parallel to the longitudinal said first operaton said support member having a first slot-like recess adjacent to and generally parallel with said member edge, and a locating pin on said operator extension closely received in said slot-like recess to confine movement of said operator extension to a direction substantially parallel to said member planar edge; an adjustable temperature control for regulating the conditioning medium supply means and fan motor in response to room temperature conditions; and a second operator pivotally secured to said support member, means securing said second operator to said adjustable temperature contol, an actuating arm secured to' said second operator for lost'rnotion in a direction substantially perpendicular 'to, the second operatorepivot axis for manipulating said second operator, 'said actuating arm extending beyond said support member-edge to accommodate manual movement of said second operator; a second slot-like recess in said'support member colinear with said support member first slot-like recess, and a locating pin on said'seco'nd operator actuating arm closely received for regulating said vent passage; an exhaustpassage con 7 V necting the outlet side'of the fan with the outside; a-

second damper for regulating said exhaust passage; means for resiliently holding said first and second dampers in said second slot-like recess to confine movement'of said second operator actuating arm to a direction substantially parallel to said support member planar edge.

7 References Cited by the Examiner I p V V V UNITED STATES PATENTS 2/44 Ederhart 62-427 2,488,589 ,11/49 Ederhart 62-427 2,711,088 6/55 'Hess 62-427 2,760,353 8/56 Kuhlenschmidt 62427 2,811,022 10/57 Lathrop 62--427 2,858,678 11/58 Rose a; 62-427 in closed position; and means for actuating said first and second dampers including a support member having WILIAM WYE, Pr mary Examiner. ROBERT A. OLEARY, Examiner. 

11. IN A ROOM AIR CONDITIONER, THE COMBINATION OF A COMPARTMENT WITH A HEAT EXCHANGE COIL THEREIN; MEANS ADAPTED WHEN ACTUATED TO SUPPLY CONDITIONED MEDIUM TO THE COIL; A MOTOR OPERATED FAN FOR CIRCULATING ROOM AIR THROUGH THE COMPARTMENT; A VENT PASSAGE CONNECTING THE INLET SIDE OF THE FAN WITH THE OUTSIDE; A FIRST DAMPER FOR REGULATING SAID VENT PASSAGE; AN EXHAUST PASSAGE CONNECTING THE OUTLET SIDE OF THE FAN WITH THE OUTSIDE; A SECOND DAMPER FOR REGULATING SAID EXHAUST PASSAGE; MEANS FOR RESILIENTLY HOLDING SAID FIRST AND SECOND DAMPERS IN CLOSED POSITION; AND MEANS FOR ACTUATING SAID FIRST AND SECOND DAMPERS INCLUDING A SUPPORT MEMBER HAVING AT LEAST ONE SUBSTANTIALLY PLANAR EDGE, A FIRST OPERATOR PIVOTALLY SECURED TO SAID SUPPORT MEMBER BETWEEN OPPOSITE ENDS THEREOF FOR LIMITED LOST MOTION, MEANS FOR RELEASABLY RETAINING SAID FIRST OPERATOR IN SELECTED POSITION, A LINK CONNECTED BETWEEN ONE END OF SAID FIRST OPERATOR AND SAID FIRST DAMPER WHEREBY MOVEMENT OF SAID OPERATOR IN ONE DIRECTION FROM A DAMPER CLOSED POSITION OPENS SAID FIRST DAMPER AGAINST SAID RESILIENT HOLDING MEANS TO VENT THE ROOM, A SECOND LINK CONNECTED BETWEEN THE OTHER END OF SAID OPERATOR AND SAID EXHAUST DAMPER WHEREBY MOVEMENT OF SAID OPERATOR IN THE OPPOSITE DIRECTION FROM SAID DAMPER CLOSED POSITION OPENS SAID SECOND DAMPER AGAINST SAID RESILIENT HOLDING MEANS TO EXHAUST THE ROOM, SAID FIRST OPERATOR HAVING AN ARMLIKE EXTENSION WITH A TERMINAL END OUTSIDE SAID SUPPORT MEMBER EDGE TO ACCOMMODATE MANUAL MOVEMENT OF SAID FIRST OPERATOR, SAID SUPPORT MEMBER HAVING A FIRST SLOT-LIKE RECESS ADJACENT TO AND GENERALLY PARALLEL WITH SAID MEMBER EDGE, AND A LOCATING PIN ON SAID OPERATOR EXTENSION CLOSELY RECEIVED IN SAID SLOT-LIKE RECESS TO CONFINE MOVEMENT OF SAID OPERATOR EXTENSION TO A DIRECTION SUBSTANTIALLY PARALLEL TO SAID MEMBER PLANAR EDGE; AN ADJUSTABLE TEMPERATURE CONTROL FOR REGULATING THE CONDITIONING MEDIUM SUPPLY MEANS AND FAN MOTOR IN RESPONSE TO ROOM TEMPERATURE CONDITIONS; AND A SECOND OPERATOR PIVOTALLY SECURED TO SAID SUPPORT MEMBER, MEANS SECURING SAID SECOND OPERATOR TO SAID ADJUSTABLE TEMPERATURE CONTROL, AN ACTUATING ARM SECURED TO SAID SECOND OPERATOR FOR LOST MOTION IN A DIRECTION SUBSTANTIALLY PERPENDICULAR TO THE SECOND OPERATOR PIVOT AXIS FOR MANIPULATING SAID SECOND OPERATOR, SAID ACTUATING ARM EXTENDING BEYOND SAID SUPPORT MEMBER EDGE TO ACCOMMODATE MANUAL MOVEMENT OF SAID SECOND OPERATOR; A SECOND SLOT-LIKE RECESS IN SAID SUPPORT MEMBER COLINEAR WITH SAID SUPPORT MEMBER FIRST SLOT-LIKE RECESS, AND A LOCATING PIN ON SAID SECOND OPERATOR ACTUATING ARM CLOSELY RECEIVED IN SAID SECOND SLOT-LIKE RECESS TO CONFINE MOVEMENT OF SAID SECOND OPERATOR ACTUATING ARM TO A DIRECTION SUBSTANTIALLY PARALLEL TO SAID SUPPORT MEMBER PLANAR EDGE. 